The investigators propose to determine the age-specific incidence of dementia and Alzheimer's disease and the clinical course of thee conditions in Chinese subjects over age 65 in Shanghai by carrying out a five year reevaluation of subjects first studied in 1987. The initial community survey of 5,055 elderly was carried out in the Jing-An district of Shanghai in 1987 by a collaborative effort of the Shanghai Institute of Mental Health and scientists then at the University of Illinois in Chicago and the University of California at San Diego. During this first survey the age- specific prevalence of dementia was determined and found to be similar to, although at the lower limits of, that found in other countries. Two-thirds of the cases met the accepted clinical criteria for Alzheimer's disease. Of particular interest was the finding of the higher prevalence of dementia in women than in men over the age of 75 and a higher prevalence among those who had received no formal education early in life. The 1992 follow-up of those who were age 65 or older in 1987 will provide data on accuracy of initial diagnosis, age-specific incidence and the effect of education, gender, and differential mortality on prevalence figures, and will provide information concerning other putative risk factors, the clinical characteristics and rate of decline observed in Alzheimer's disease in Shanghai and caregiver burden in this society.